The present invention relates to a vehicular rotational apparatus that has a rotary body and an electric motor. The rotary body is operably connected to a rotary shaft, which drives a mechanism, and transmits power to the rotary shaft from an external drive source. The electric motor selectively drives the rotary shaft.
A typical compressor (vehicular rotational apparatus) drives a compressing mechanism for compressing refrigerant by selectively using power from an external drive source and power from an electric motor, which is located on the compressor. Japanese Laid-Open Patent Publication No. 11-30182 discloses such compressor.
The compressor of the above publication has a pulley for receiving power from the external drive source and a rotary shaft for driving the compression mechanism. A pulley one-way clutch is located in a power transmission path between the pulley and the shaft. A motor one-way clutch is located in a power transmission path between the electric motor for driving the compression mechanism and the shaft.
With this structure, the compression mechanism is driven by selectively using power from the external drive source and power from the electric motor. Further, when driving the compression mechanism by power from the external drive source, the electric motor (or more specifically, a rotor of the electric motor) is prevented from being rotated. As a result, power transmitted from the external drive source to the rotary shaft is prevented from being consumed unnecessarily for purposes other than driving compression mechanism.
In the above structure, the pulley is supported by a housing, which accommodates the compression mechanism, with a bearing. Thus, even when the pulley receives external force in the radial direction by the tension of a belt wound about the pulley, the external force is not easily applied to the shaft.
Also, the pulley one-way clutch and the bearing are arranged to overlap each other in the axial direction of the shaft. In this case, the size of the compressor is reduced in the axial direction of the shaft as compared to a structure in which the one-way clutch and the bearing are arranged not to overlap each other in the axial direction.
In the above structure, the size of the compressor is reduced by using the one-way clutch instead of an electromagnetic clutch. However, the location of, for example, the electric motor to reduce the size of the compressor is not disclosed.
Accordingly, it is an objective of the present invention to provide a vehicular rotational apparatus that drives a mechanism by selectively using power from an external drive source and power from an electric motor, and is easily minimized in the axial direction of a rotary shaft.
To achieve the above objective, the present invention provides a rotational apparatus that is driven by an external drive source. The rotational apparatus includes a housing, a rotary shaft, a first rotary body, an electric motor, a bearing, a first one-way clutch, and a second one-way clutch. The rotary shaft is supported by the housing. The first rotary body is operably connected to the rotary shaft and includes a power transmission portion. When power is transmitted from the external drive source to the power transmission portion, the first rotary body is rotated. The electric motor drives the rotary shaft and includes a second rotary body, which is operably connected to the rotary shaft, a commutator, which is located on the second rotary body, and a brush device, which contacts the commutator. The bearing is located between the first rotary body and the housing. The first rotary body is supported by the housing with the bearing. The first one-way clutch is located between the first rotary body and the rotary shaft. The second one-way clutch is located between the second rotary body and the rotary shaft. At least two of the bearing, the first one-way clutch, the second one-way clutch, and the brush device overlap each other in the axial direction of the rotary shaft. The electric motor overlaps the power transmission portion in the axial direction of the rotary shaft.
The present invention also provides a rotational apparatus that is driven by an external drive source. The rotational apparatus includes a housing, a rotary shaft, a first rotary body, an electric motor, a bearing, and a one-way clutch. The rotary shaft is supported by the housing. The first rotary body is operably connected to the rotary shaft and includes a power transmission portion. When power is transmitted from the external drive source to the power transmission portion, the first rotary body is rotated. The electric motor drives the rotary shaft and includes a second rotary body, which is operably connected to the rotary shaft, a commutator, which is located on the second rotary body, and a brush device, which contacts the commutator. The bearing is located between the first rotary body and the housing. The first rotary body is supported by the housing with the bearing. The one-way clutch is located between the first rotary body and the rotary shaft. At least two of the bearing, the one-way clutch, and the brush device overlap each other in the axial direction of the rotary shaft. The electric motor overlaps the power transmission portion in the axial direction of the rotary shaft.
A further aspect of the present invention is a rotational apparatus that is driven by an external drive source. The rotational apparatus includes a housing, a rotary shaft, a first rotary body, an electric motor, a bearing, a first one-way clutch, and a second one-way clutch. The rotary shaft is supported by the housing. The first rotary body is operably connected to the rotary shaft and includes a power transmission portion. When power is transmitted from the external drive source to the power transmission portion, the first rotary body is rotated. The electric motor drives the rotary shaft and includes a second rotary body, which is operably connected to the rotary shaft. The bearing is located between the first rotary body and the housing. The first rotary body is supported by the housing with the bearing. The first one-way clutch is located between the first rotary body and the rotary shaft. The second one-way clutch is located between the second rotary body and the rotary shaft. At least two of the bearing, the first one-way clutch, and the second one-way clutch overlap each other in the axial direction of the rotary shaft. The electric motor overlaps the power transmission portion in the axial direction of the rotary shaft.
The present invention further provides a rotational apparatus that is driven by an external drive source. The rotational apparatus includes a housing, a rotary shaft, a first rotary body, an electric motor, a bearing, and a one-way clutch. The rotary shaft is supported by the housing. The first rotary body is operably connected to the rotary shaft and includes a power transmission portion. When power is transmitted from the external drive source to the power transmission portion, the first rotary body is rotated. The electric motor drives the rotary shaft and includes a second rotary body, which is operably connected to the rotary shaft. The bearing is located between the first rotary body and the housing. The first rotary body is supported by the housing with the bearing. The one-way clutch is located between the first rotary body and the rotary shaft and overlaps the bearing in the axial direction of the rotary shaft. At least part of the electric motor overlaps the power transmission portion in the axial direction of the rotary shaft and is located radially inward of the power transmission portion.